A lateral flow immunoassay based on chemisorbed probes in virtue of hydrogen bond receptors on the BiS NPs.

Improving detection sensitivity is still a major research emphasis for lateral flow immunoassay (LFIA). Increasing the binding efficiency and stability of the probe is an achievable and effective solution. In this work, we developed a highly sensitive lateral flow immunoassay for clenbuterol detection by using bismuth sulfide nanoparticle (BiS) nanoparticles (NPs) as a novel marker. Here, BiS NPs can link with the antibody by hydrogen bonding to improve the performance of the probe, e.g., stability and sensitivity. Benefiting from the direct hydrogen bonding between BiS NPs and the monoclonal antibody (mAb), high sensitivity is obtained by the proposed LFIA with a lower visible detection limit of 0.1 ng mL and a cut-off value of 4 ng·mL for CLE detection, which is 5-fold and 7.5-fold improved than the conventional Au NPs based LFIA. In addition, the encouraging practical application results in milk, pork, and beef show that the bismuth sulfide nanoparticle has a great popularizing potential in the performance promotion of LFIAs for food safety monitoring.